FACEBOOK and Tinder are increasingly being used by criminals to help them commit violent offences such as rape and murder.
Queensland police mentioned the involvement of social media platforms in their official reports into at least 20 violent crimes last year - including two murders, rapes, assaults, domestic violence and a missing person case.
Police said social media made it easier to groom a victim and to locate potential targets. Experts warn that default settings are often "public".
In one case involving Facebook, a victim was stalked, with the accused attending their home and business.
They were caught by police with digital images of the victim's address and "specific details relating to the victim's day-to-day behaviour and business affairs", according to documents released under Right to Information.
They were charged with conspiracy to murder.
In a murder case involving the platform, the victim met with a person who drove them to an area before being stabbed.
The victim was then dragged from the road and had their clothes removed.
Police documents also reveal that Facebook was involved or mentioned in 35 rape investigations, a murder and a conspiracy to murder offence between 2013 and 2015.
A police officer said social media "made it easier to 'groom' a victim, locate someone you want to harm, track people's movements".
"Unfortunately it's how people socialise these days so it's merely an extension of how you connect with victims," the officer said.
With social media now enmeshed in many people's lives, users have been repeatedly warned about how much they post on the platforms and how it could open them up to being targeted.
Sarah-Jane Peterschlingmann, managing director of cloud hosting company ATech, said most people thought that when they put something on Facebook or Tinder it was like a private conversation between themselves and their friends.
With default settings often "open" to the public, Ms Peterschlingmann said users should review their privacy settings regularly and never post anything they would not be happy for everyone to see.
She said people should assume that anyone could access posts at any time even if they posted the information in a way that appeared private.
"You would expect that it would be OK to talk freely on social media the same way you would on a phone call, and that no one else would have access to that information, but it doesn't always work out that way," she said.
An examination of cases by The Courier-Mail shows social media is also regularly emerging as a tool in police investigations.
Social media was used by detectives to help their investigation into murdered Brisbane man Samuel Thompson.
When police were told of his disappearance in March, officers found he had not accessed social media. Family and friends said it was out of character.
And after one of his alleged murderers, Roberto Boscaino, was put under surveillance, police seized a pair of Ray Ban sunglasses he threw away in a cemetery garbage bin that officers suspected belonged to Mr Thompson.
Officers sifted through old photos on his Facebook account, finding him wearing a similar pair in a photo posted online about a year ago.
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